You could try fusible interfacing.
If just a temporary stop you need then maybe dissolve some wss in water and brush it on, let it dry and make your project. Keep in mind it will wash out later.
Perhaps clear fingernail polish? Not too sure about that one though lol.

I am making key fob's so they will not go in the laundry

je pense qu'il existe de la colle spéciale pour cela

You can buy Fray Check in the Netherlands, I did, bought in a shop that sells quilting materials. It comes in a 22.5 ml bottle and is pricey as it's imported from the USA.
But you might use Vlieseline H180 (that's a thin variety) or Vliesofix which you iron on the patch and after removing the paper backing iro to the material you applique on. Both available from any fabric store.

If you would like I will get you some bottles and send them to you. E-mail me at: margiepink@rocketmail.com